When you run these numbers what value do you use for the flow in the line at the static pressure reading, our do you assume a hydrant on a dead end main with zero flow for an actual static pressure reading? Mark at Aero
-----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Brad Casterline Sent: Thursday, June 26, 2014 9:58 AM To: [email protected] Subject: RE: Underground Piping Makes sense Todd. I believe a flow test measures the friction loss from the source to the gauged hydrant, with a negligible amount of velocity head loss. Say we get 75,72,500. If we know 8" X 1500 feet total, using Q^1.85 and rearranging H-W, we can get the C-Factor=140. If we got 75,68,500 with the same 8 by 1500, we would get C=85. Also, using Q^2 and C=140, we would get the same 7 pound drop. I guess what I am saying is, the flow test is a measure of the several factors, as a whole, that are usually unknown without doing a lot of digging, literally ;) Brad -----Original Message----- From: Todd - Work [mailto:[email protected]] Sent: Thursday, June 26, 2014 10:18 AM To: [email protected] Subject: Re: Underground Piping Remember, all of our formulas are approximations. They can be more accurate in some situations and less in others. The velocity restrictions of years back were originally to compensate for the inaccuracies in the formula when velocity exceeded a certain amount. Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT www.fpdc.com 860-535-2080 (ofc) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
